Nanoparticles have shown great promise as therapeutic agents and as delivery agents for other drugs. Similarly, nanoparticles of organic-inorganic composites are attractive because they combine the low mass, low cost, ease of processing of polymer organics with the unique functionality of metal centers. However, there remains a need in the art of nanoparticle preparation to overcome poor miscibility, dispersion stability and interfacial strength problems that often limit the practical end use of many nanoparticle formulations.
The discovery of nanoscale ionic material (NIM) compositions, as described by E. P. Giannelis and A. B. Bourlinos in US Patent Application 2007/0254994, and by N. Fernandes and E. P. Giannelis in WO 2012129279, is one solution to the problem of poor nanoparticle dispersion stability in that the agglomeration of individual nanoparticles is prevented by the direct chemical tethering of a polymeric solvent (canopy) to individual nanoparticles (inorganic metal oxide core and stabilizing corona). In a particular embodiment, the NIM compositions spontaneously form nanoscale ionic liquid (NIL) material compositions that are characterized by transport and free flowing fluid properties remarkably similar to those of simple molecular liquids, but with negligible vapor pressures. There remains a need in this art for new inorganic metal oxide cores and for novel coronas to which the solvent canopy can be applied.
In addition, there remains a need for processes that directly prepare dispersions of metal oxide nanoparticles, for example, without isolation of the nanoparticles, in higher yield, in a shorter period of time and at higher suspension densities, that are biocompatible and sufficiently small in particle size (e.g. sufficiently small in size to evade detection by an immune system when administered as a drug), uniform in size frequency distribution, and stable in a wide range of biological media.